My puppy was diagnosed with parvo 3 days ago. The vet said that she is doing great since she has been hydrating herself and eating by herself without us having to force her. She also has been taking her medicine and not throwing up.
But today, my husband cleaned out one of our trash cans (that has a little hole on the top)because he found it full of maggots. We have fixed the maggot problem by covering the hole so the flies can not get in there.
We had let our puppy outside to do her business while he was cleaning out the trash can.. he turned around and saw her eating maggots.

He grabbed her and brought her inside. Do you think it will harm her? We were planning on taking her to the vet tomorrow anyway to get checked out.. but I hope that the maggots didn't derail all of her process she has already made..

I really doubt it. Maggots do not thrive in stomach acid. Think of it as another disgusting form of protein
They might give her a belly ache however, especially since she's recovering from a serious illness. If it were me, I would call an emergency vet for a definitive recommendation.

I agree with Badger and I don't think they will harm her. We are not vets here though so to really ease your thoughts I would call your vet and ask. Most vets have an emergency number when they are closed and the answering service would be able to contact him/her and ask them to give you a call. Good luck and hope your puppy has a complete recovery.

Eating maggots, while a very repelling image, usually will not cause any lasting harm in an immunocompetent individual. Obviously, what maggots eat to sustain themselves can be vile and infectious. If no vomiting/diarrhea/fever shortly after ingestion (48 to 72 hours), then no harm done.